Patent GB-653066-A (GB)
Title: Improvements relating to methods of and means for coating metal
IPC: B22D13/06
Filed: 1948-03-22
Abstract: 653,066. Casting-machines. THEVENIN, M. March 22, 1948, Nos. 8453 and 8454. Convention dates, March 21, 1947 and March 10, 1948. [Class 83 (i)] Pouring-apparatus ; clamping moulds.-Openable moulds are passed in succession under a furnace taphole and this is automatically opened when a mould is located thereunder and closed when the level of poured metal reaches a desired level. The tap-hole is preferably controlled by electromagnetic means. Two chill moulds are carried by arms 21<SP>1</SP> of a rotary table 21 which is given semi-revolutions, separated by rest periods of equal duration, by a table 22 rotated continuously by a motor M. The table 22 has a nose 22<SP>1</SP>, Fig. 3, adapted to engage either of two pins 26 vertically movable in the table 21 which is thus rotated. As a mould X moves from the position A, Fig. 3, it is closed by a fixed cam 55 engaging a spring 30, Fig. 2, on a lever 48<SP>1</SP> and as it reaches the position directly below the tap hole 11 the pin 26 in engagement with the nose 22<SP>1</SP> is pushed up by a fixed cam 28 so that it is no longer engaged by the nose and the table 21 is arrested by a stop 29 engaging a projection 29<SP>1</SP> on the movable half 45 of the closed mould opposite that under the tap-hole 11. In this position contacts F, G, Fig. 4, of a circuit 64 broken at J, J<SP>1</SP> engage and push up against the action of springs S, insulated contact bars T to close contacts D, D<SP>1</SP> and E, El so that a magnet A is energized and the valve rod 12 raised to open the tap-hole 11. When the metal rises in the mould and reaches contacts J, J<SP>1</SP> a circuit is established that energizes a magnet B and brakes the first circuit at L, L<SP>1</SP> so that the pin 12<SP>1</SP> lowers and then rotates the rod 12 by reason of the inclined slot 13, thus closing the tap-hole. If the mould has not been fully closed, contacts K, K<SP>1</SP> remain closed and the contacts L, L<SP>1</SP> are kept open so that no metal is poured. Castings, extracting.-While the table 22 makes another semi-revolution it engages a pin 261 projecting upwardly from an arm 33 pivoted about the centre of the tables and causes it to pull a cord 35 attached to a spring returned slide 65 which engages the arm 48<SP>1</SP>, free from the cam 55, and moves it, as shown in Fig. 2, to withdraw cores 53<SP>1</SP> and then the mould part 45, freeing it from the stop 29 and allowing the casting to fall out through a hole 69 in the arm 21<SP>1</SP>. A fixed cam 28<SP>1</SP> then depresses the pin 26<SP>1</SP> and the slide 65 and arm 33 are returned by the spring 67. When the table 22 has completed this semi-revolution the nose 221 engages the other pin 26 and the other mould passes through the same cycle of operations as the first and then these operations are repeated as often as required. If the casting should stick in either half of a mould it is detached as the open mould travels by fixed springs 68. Movement of the table 21 may be steadied by a brake. The open mould may be cooled by a jet of fluid. In a modification, instead of the lost-motion device for withdrawing the core and mould half, the lever 48, Fig. 5, is arranged horizontally and moves the frame 64, carrying the mould half 45, directly, the core slide 53 through link 51 and a lever 52 pivoted at 71 on the frame 64 and ejectors 62 through a roller 57 and lever 54 pivoted to the frame 64 at 59. Where aluminium or an alloy thereof is to be cast the tap rod may be coated with a composition including graphite and engage a graphitecoated seating. The Specification as open to inspection under Sect. 91 refers to arrangements in which the moulds move rectilinearly and also in which some only of the operations are automatic. This subject-matter does not appear in the Specification as accepted.